Salam, I have some questions regarding Essay writing in CSS and it would be very helpful if anyone can help me clear my confusion.

1- Should outline contain everything that we have to discuss in our Essay? Like an introduction to every other heading.

2- Is it necessary to write an outline in the real exam too?

3- Is it necessary to write the headings before starting the paragraph which is being used in the outline?
For example, we used 'Why this is happening' in our outline should we also put this in heading before explaining it further in the essay.

4- If we write an outline before, do we really have to stick with it in the essay?

Some of these questions might sound stupid, or maybe I can not explain it clearly but it would be really helpful if somebody can answer it as it is the only subject that is getting difficult for me to grasp at the moment.

Thanks in advance.